Maximum Subarray 連續子陣列最大和

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

For example, given the array [−2,1,−3,4,−1,2,1,−5,4],
the contiguous subarray [4,−1,2,1] has the largest sum = 6.

More practice:

If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.

此題為經典的求連續子陣列最大和問題，除了暴力的解法，想辦法用O(n)時間來做。

直接貼程式碼：

class Solution {
public:
    int maxSubArray(int A[], int n) {
        if(A == NULL || n < 1)
            return -1;
            
        int max = A[0];
        int temp = 0;
        
        for(int i = 0 ; i < n ; i++){
            if(temp < 0)
                temp = A[i];
            else
                temp += A[i];
                
            if(temp > max)
                max = temp;
        }
        
        return max;
        
    }
};